What case law has not addressed until recently, however, is whether a co-owner is (or should be) able to settle claims for infringement of a jointly held copyright by third parties without the consent of some or all of the other co-owners. Generally, as noted above, a copyright co-owner cannot infringe his or her own work. It follows then that a license to the defendant from one joint owner will be an effective defense to an infringement action brought by another joint owner.
This is so even if the licensing co- owner collects only a portion of the full license value from the defendant. But a prospective license authorizing future use is obviously not synonymous with a settlement agreement absolving one of liability for past infringement, and need not necessarily be treated similarly by the law.